IB Questionbank

Topic 4.3 [9 marks]

A 1. Two wave pulses, each of amplitude , approach each other. They then superpose before continuing in their original directions. [1 mark] What is the total amplitude during superposition and the amplitudes of the individual pulses after superposition?

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[N/A] 2. Two pulses are travelling towards each other. [1 mark]

What is a possible pulse shape when the pulses overlap?

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[N/A]

Unpolarized light of intensity I is incident on the first of two polarizing sheets. Initially the planes of polarization of the sheets are 3. 0 [1 mark] perpendicular.

I0 Which sheet must be rotated and by what angle so that light of intensity can emerge from the second sheet? 4

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4. A beam of unpolarized light is incident on the first of two parallel polarizers. The transmission axes of the two polarizers are initially [1 mark] parallel.

The first polarizer is now rotated about the direction of the incident beam by an angle smaller than 90°. Which gives the changes, if any, in the intensity and polarization of the transmitted light?

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5. Properties of waves are [1 mark] I. polarization II. diffraction III. refraction

Which of these properties apply to sound waves?

A. I and II B. I and III C. II and III D. I, II and III

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[N/A] A point source of light of amplitude A gives rise to a particular light intensity when viewed at a distance from the source. When the 6. 0 [1 mark] amplitude is increased and the viewing distance is doubled, the light intensity is doubled. What is the new amplitude of the source?

A. 2A0

B. 2√2 A0

C. 4A0

D. 8A0

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A point source emits sound waves of amplitude A. The sound intensity at a distance d from the source is I. What is the sound 7. [1 mark] intensity at a distance 0.5d from the source when the source emits waves of amplitude 2A?

A. 16I

B. 4I

C. I

D. 1 I 4

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[N/A] A water wave moves on the surface of a lake. P and Q are two points on the water surface. The wave is traveling towards the right. 8. [1 mark]

The diagram shows the wave at time t = 0. Which graph shows how the displacements of P and Q vary with t?

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[N/A] Horizontally polarized light of intensity I enters a polarizer P whose polarization axis makes an angle of θ degrees with the 9. 0 [1 mark] horizontal. Light from P is then incident on a polarizer A with fixed vertical polarization axis.

The angle θ is varied from 0 to 90 degrees. Which of the following represents the variation with θ of the intensity I of the light transmitted through A?

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[N/A]